exoskeleton

Catch up on your Hackaday with this week’s podcast. Mike and Elliot riff on the Bluepill (ST32F103 boards), blackest of black paints, hand-crafted sorting machines, a 3D printer bed leveling system that abuses some 2512 resistors, how cyborgs are going mainstream, and the need for more evidence around airport drone sightings.

Stream or download Episode 4 here, and subscribe to Hackaday on your favorite podcasting platform! You’ll find show notes after the break.

Every technological advancement seems to have a sharp inflection point, a time before which it seems like any early adopters are considered kooks, but beyond which the device or service quickly becomes so mainstream that non-adopters become the kooky ones. Take cell phones, for example – I clearly remember a news report back in the 1990s about some manufacturers crazy idea to put a digital camera in a phone. Seemingly minutes later, you couldn’t buy a phone without a camera.

It seems like we may be nearing a similar inflection point with a technology far more complex and potentially far more life-altering than cameras in cell phones: powered exoskeletons. With increasing numbers of news stories covering advancements in exoskeletal assistants for the elderly, therapeutic applications for those suffering from spinal cord injuries and neurodegenerative diseases, and penetration into the workplace – including the battlefield – as amplifiers of human effort, it’s worth taking a look at where we are with exoskeletons before seeing someone using one in public becomes so commonplace as to go unnoticed.

Levers are literally all around us. You body uses them to move, pick up a pen to sign your name and you’ll use mechanical advantage to make that ballpoint roll, and that can of soda doesn’t open without a cleverly designed lever.

I got onto this topic quite by accident. I was making an ornithopter and it was having trouble lifting its wings. For the uninitiated, ornithopters are machines which fly by flapping their wings. The problem was that the lever arm was too short. To be honest, as I worked I wasn’t even thinking in terms of levers, and only realized that there was one after I’d fine-tuned its length by trial and error. After that, the presence of a lever was embarrassingly obvious.

I can probably be excused for not seeing a lever right away because it wasn’t the type we most often experience. There are different classes of levers and it’s safe to say that most people aren’t even aware of this. Let’s take a closer look at these super useful, and sometimes hidden mechanisms known as levers.

Wearables and robots don’t often intersect, because most robots rely on rigid bodies and programming while we don’t. Exoskeletons are an instance where robots interact with our bodies, and a soft exosuit is even closer to our physiology. Machine learning is closer to our minds than a simple state machine. The combination of machine learning software and a soft exosuit is a match made in heaven for the Harvard Biodesign Lab and Agile Robotics Lab.

Machine learning studies a walker’s steady gait for twenty periods while vitals are monitored to assess how much energy is being expended. After watching, the taught machine assists instead of assessing. This type of personalization has been done in the past, but the addition of machine learning shows that the necessary customization can be programmed into each machine without a team of humans.

While medical facilities continue to improve worldwide, access to expensive treatments still eludes a vast amount of people. Especially when it comes to prosthetics, a lot of people won’t be able to afford something so personalized even though the need for assistive devices is extremely high. With that in mind, [Guillermo Herrera-Arcos] started working on ALICE, a robotic exoskeleton that is low-cost, easy to build, and as an added bonus, 100% Open Source.

ALICE’s creators envision that the exoskeleton will have applications in rehabilitation, human augmentation, and even gaming. Also, since it’s Open Source, it could also be used as a platform for STEM students to learn from. Currently, the team is testing electronics in the legs of the exoskeleton, but they have already come a long way with their control system and getting a workable prototype in place. Moving into the future, the creators, as well as anyone else who develops something on this platform, will always be improving it and building upon it thanks to the nature of Open Source hardware.

Prosthetic and assistive technologies have come have come a long way in recent years. When there are not only major medical research organizations, but individuals getting on board designing tools to improve the lives of others? That’s something special. Enter a homebrew essay into this field: ExoArm.

Attached to the body via what was available — in this case, the support harness for a gas-powered weed-eater — which distributes the load across the upper body and an Arduino for a brain, ExoArm designer [Kristjan Berce] has since faced roadblocks with muscle sensors meant to enable more instinctive control. So — for now — functionality is limited to a simple up and down motion controlled by two switches. It is worth noting that the down switch is currently mounted in such a way that when the user moves their arm down, the ExoArm follows suit, so there is some natural feel to using the arm in its present iteration.

When we think of exoskeletons, we tend to think along comic book lines: mechanical suits bestowing superhero strength upon the villain. But perhaps more practical uses for exoskeletons exists: restoring the ability to walk, for instance, or as in the case of these exoskeleton shorts, preventing hip fractures by detecting and correcting falls before they happen.

Falls and the debilitating injuries that can result are a cruel fact of life for the elderly, and anything that can potentially mitigate them could be a huge boon to public health. Falls often boil down to loss of balance from slipping, whether it be a loose rug, a patch of ice, or even the proverbial banana peel. The “Active Pelvic Orthosis” developed by [Vito Monaco] and colleagues seeks to sense slips and correct them by applying the correct torque to the hip joints. Looking a little bulky in their prototype form and still tethered to an external computer, the shorts have motors with harmonic drives and angle sensors for each hip, plus accelerometers to detect the kinematic signature of a slip. The researchers discovered that forcing the leg that slipped forward while driving the stable leg back helped reduce the possibility of a fall. The video below shows the shorts in action preventing falls on a slip-inducing treadmill.

At the Hackaday Unconference in Pasadena, we heard from [Raul Ocampo] on his idea for autonomous robots to catch falling seniors. Perhaps wearing the robot will end up being a better idea.